#include <stdio.h>
extern char**environ;
#include<unistd.h>
int main()
{
    printf("程序开始。。。\n");
    
    //execl("/usr/bin/ls","./ls","-a","-l");

    printf("程序结束。。。\n");
    execl("/usr/bin/ls","./ls","-a","-l",NULL);
    return 0;
}

